Even if you’ve played Doom 2016, you might feel a bit lost in Doom Eternal and its more complex and expansive story. The game starts with a massive demonic invasion of Earth, without revealing what has happened since the previous game, and you’re given your own spaceship, which is also a castle for some reason. And now the story expansion is happening, adding even more confusion and weirdness to an already extensive and complicated story. Even if you think you know the Doom story well, you might feel lost starting id Software’s latest game. It expects you to know everything from the previous Doom game and have a good understanding of 20 years of Doom history. Read the title and read a ton of collectible codex entries to fill in the gaps.

You don’t necessarily need to dig deep into Doom Eternal’s story to enjoy the complex combat, but it does tell a pretty complex story if you’re interested. The problem is that you’ll have to do a lot of work yourself to catch up, including finding the many collectibles scattered throughout the game, which will give away some crucial information about Doom’s story, but if you want to just go ahead and see it all, we’ve got good news for you: we’ve compiled the entire story and lore here.

The Makyrs

Before we get into the story of the Doom Slayer and his brutal crusade to destroy all demons, we need to introduce you to all the other characters who play important roles in Doom Eternal but that you probably haven’t heard of. The big bad guy in Doom Eternal is Kahn Makir, who represents a human race on a planet called Urdak. They are essentially angels and this planet is basically a techno heaven. Urdak is so special that it actually exists outside of physical reality and it is nearly impossible for the Makirs to get there if they don’t want to.

Long ago, the Makirs were created or rather met and elevated by a being called the Father. It is not entirely clear who or what the Father was, but his essence remained on Urdak for a long time and became the center of Makir society. During this time the Makirs went through a process called the Transfiguration. They were very long-lived, but at some point the Makirs began to decline and the Transfiguration appears to be a kind of cycle of death and rebirth. It sounds like the Makirs are actually individuals who develop a larger collective consciousness after death, so the Transfiguration seems like a kind of reincarnation through this process.

Every 10,000 years the Makirs choose and create a leader, or khan, from their collective consciousness. This person leads the Makirs until the next khan is elected, and during this time the Makirs are physically unable to oppose the khan. There are pre-built term limits on the khan Makirs through the Transfiguration, but the khans have a lot of power and they may not want to give it up. This will become relevant in a moment.

So at some point something strange happens and the father just disappears as is. Makir lore suggests that the father’s essence may have been stolen by a Makir named Seraphim, but the details are hazy. What’s important is that the father is gone and it disrupts Makir society, especially the Transfiguration, which now sounds terrible to the Makirs (though we don’t know exactly how that happened). Basically, the Makirs are fearful of the Transfiguration failing, and the Khan is looking for a way to stop it.

The Story Of The Sentinels

Meanwhile, on a planet called Argent D’Nur, a group of powerful space warriors rises up and forms a coven. These people call themselves the Argentas, and they will conquer the harsh, horrifying, and apparently monster-infested world. They form an army of holy knights called the Nightwatchers, whose mission is to protect Argent D’Nur, ensure justice, and more.

The Argentans are such skilled warriors that they somehow attract the attention of the Makirs, who visit Argent D’Nur and are practically worshipped as gods. Together with Kahn Makir, the Sentinels become a force to conquer other planets. They use Makir technology to support the magic and technology that the Sentinels had already created with the ancient gods of Argent D’Nur, strange creatures called Wraiths. The Sentinels begin to travel to other planets and convert the Machians to worship them as well, and generally everyone gets along well and prospers.

It’s not entirely clear if the Machians are organic or some sort of massive artificially intelligent computer system, but their collective mind was able to analyze probabilities and plan possible futures. The Machians had always seen the same thing in all of their visions of the future: Sentinel warriors who would eventually destroy them, which they called the Impurity. They created something called the Divinity Machine and asked the Sentinels to use it on their warriors to test them for “impurities” that might betray them before the Unholy bring catastrophe to Urdak. The Sentinels agreed. It’s not entirely clear what the Divinity Machine is or what it does, but it was apparently on Argent d’H’Nur, where it was conveniently placed for use later in the story.

Doom Guy

Meanwhile, on Mars, security guards working at a research facility are caught up in a demonic invasion after a scientist working on teleportation technology accidentally opens a portal to Hell. This Doom Guy embarks on a John Wick-esque mission of rage after his rabbit Daisy is killed by a demon. He rampages through the Martian facility by sheer force of will. Later, in Doom 2, the demons try to conquer Earth, and he battles them there to repel the invasion. In Final Doom, demons attack another facility on one of Jupiter’s moons. Doom Guy appears and kills everyone, making him even angrier. Eventually, Doom Guy becomes enraged and resolves to go to Hell itself and kill more demons in Doom 64.

Doom Guy has a fairly successful campaign in Hell, but after destroying the Mother of Demons, he decides to stay in Hell for a while and kill as many demons as he can. However, in a new Doom 64 level available in Doom Eternal, Doom Guy is teleported out of Hell by a demon from another boss level.

Doom Guy Arrives On Argent D’Nur

As Doom Eternal progresses, we learn the backstory of the protagonist, the Doom Slayer, and everything we’ve been told so far comes together into one big story. When the Archdemon banished Doom Guy from Hell, perhaps by accident, he sent him to Argent d’Hunur. There, Doom Guy is found by the Sentinels and their priests, the Deeg Cult. Everything Doom Guy has been through has driven him insane, and all he knows is murder, saying things like “tear it up” and “guts, giant guts.” He becomes known as the Outlander, and the Sentinels throw him into a gladiatorial arena. There, Argenta, who broke the law, gets a chance to redeem himself in a fight, join the army, and die a glorious death.

This is the big twist in Doom Eternal. In the game, it is revealed that the protagonist from the original Doom game is actually the same person you controlled in Doom 2016 and Doom Eternal. You’ve definitely seen a lot of him at this point, but you’ve been playing the same Doom Guy all this time. Eternal fills in the gaps as to how this ordinary Space Marine was able to transform into the legendary and feared Doom Slayer.

In Doom Eternal, the twist is revealed in a cutscene where Doom Guy appears in Argent d’Hunur and is brought before two priests of the Deeg cult who must eventually be hunted, ranting about Hell and demons. Below. After all, the Sentinels and Maquills had never heard of the Hell Dimension before Doom Guy showed up. It seems likely that this may have given Kahn Maquill the idea, or at least piqued his curiosity, to explore the terrible powers of Hell.

Thanks to his lethal skills, Doom Guy excelled in the arena and won the chance to join the Sentinel army. But not long after, demon portals began opening on Argent d’Hunur, and Hell began its invasion of the planet. Sentinel and Makiar joined forces to fight them, but they found that Hell’s army was unlike any foe they had faced before. The demons used some kind of powerful energy source that dwarfed everything Sentinel and Makiar had, and they lost the war.

The Unholy Wars

The Makir and Argenta families fought against the demons for years, and Doom Guy fought alongside them, excelling on the battlefield. However, the tides turned towards the end of the war after some Sentinel priests captured a demon and studied its abilities. They discovered Essence, an energy source the demons were using. The substance was incredibly powerful, allowing them to create weapons, power cities, heal the sick, and even raise the dead.

As the war raged, the Makir and Sentinel priests discovered a way to open a portal to Hell and began siphoning off Hell’s power for their own purposes. They called it Argent Energy, and it allowed the Night Watchers to fight off hordes of demons. They used Argent Energy on the city, and Argent D’Nur became wealthier than ever. This energy was also sent to Urdak, allowing the Makir to prevent transformations and live forever. Kahn Makir became essentially omnipotent, because without transformations she could never be replaced, never challenged.

All this time the Night Watch had been a little suspicious of Argent Energy – it seemed a little too good to be true. They still trusted the Machians, but kept the Argents at bay as they continued to fight the demons.

Birth Of The Doom Slayer

Things became dire again when Demons launched a massive attack on the Argentan city of Talus Nabad (a location we will visit again in Doom Eternal). An inferno ravaged the city, killing nearly everyone there except for Doom Guy and a group of Sentinels who tried to hold out. The attack was led by a gigantic demonic giant who tried to wipe out almost everyone.

Before the end comes, a Makirian named Samur intervenes. He takes Doom Guy to the Divinity Machine where he drugs him with… something. Argent Energy can be hard to remember or keep track of. Anyway, for some reason, the machine turns Doomguy into a superhuman killing machine and he stops being Doomguy and becomes the Doom Slayer instead. Known as the protagonist of Doom 2016 and Doom Eternal. The Doom Slayer has torn apart demons and killed Titans, and for his efforts, he has earned the unprecedented honor of joining the Sentinel army on an equal footing with Argenta.

With the Doom Slayer’s help, the Sentinels start winning the battle against Hell and things are going pretty well. They venture into Hell and start fighting demons in their own realm. And then they make a horrifying discovery: the Makirs are actually the bad guys. Shocker.

The Civil War

While waging their war against the demons, the Argentans enjoyed Argent energy, as did the Makirs. Towards the end of the war, Sentinels began to find Hell’s Argent energy factories, built at the behest of Makir. It turned out that the Makirs had made a deal with Hell; in exchange for an unlimited supply of Argent energy, the Makirs would be allowed access to worlds that Hell had conquered. Alas, that Argent energy material was actually made from the tortured souls of those killed by demons. The Argentans enjoyed the prosperity brought about by the horrific deaths and suffering of their own people.

The Sentinels and their priests, the Deeg Cult, along with the Doom Slayer, were scared and decided to turn against the Maquia. They tried to teach the Argentas about the Argent energy, but most of them would not listen, either because they were blinded by their faith in the Maquia or because they did not want to give up the Argent energy. This caused a civil war to break out between the Sentinels and their king and Maquia supporters, and by this point the Maquia had already fully cooperated with the demons as allies. The Marauders fighting in Doom Eternal were former Night Sentinels who sided with the Maquia and became nasty and very hard to kill demon warriors.

The Betrayal

After many more years of fighting, the Sentinels came up with a new plan: to go to Hell and destroy Nekravor, the massive factory that supplies Urdak with Argent Energy, cutting off the Makir. And it might have worked if a major betrayal hadn’t happened.

You know the Hell Priests you have to kill in Doom Eternal? Yes, it’s the Deag cult, the Sentinel priests who are supposed to be good. They started working for the Makir, but before that they used the Sentinel Portal to reach Nekravor, where they could disperse their legions to Hell and imprison them there.

The Sentinels had another traitor, Commander Varen. He lost his son in the war, but the demons promised to save him from the torments of Hell and bring him back to life. In return, Varen gave the demons the information they needed to defeat the Sentinels with the help of Priest Deeg. Of course you can’t trust demons. Varen’s son returned to life, but not as a human. Instead, the Hellions transformed him into a gigantic giant monster called the Icon of Sin (the final boss you fight in Doom Eternal). Filled with grief and shame, Varen was banished to Hell for all eternity and became known as “The Traitor.” We meet the Traitor briefly at the beginning of Doom Eternal, and he’s still shaken by all that happened.

The Hellwalker

So at this point the Sentinels are trapped in Hell and being torn apart by demons. Most or all of them are killed and the civil war ends with a victory for Kahn Makir and his supporters, the Order of Deagh. The Makir and Argentas continue to invade planets from here, handing them over to the demons to create a constant flow of souls, creating the Argent Energy. The power makes them more and more corrupt and evil.

The Doom Slayer, on the other hand, does not die in Hell. Instead, he apparently spends many more years roaming the plains of Hell, killing demons and destroying things for all evil monsters. Things have gotten so bad that the demons have written entire legends and literature about him in their rarefied culture. In Hell, the Doom Slayer is the monster.

But eventually the demons trap the Doom Slayer. They can’t seem to kill him, but they can imprison him. The demons manage to separate him from his equipment and imprison him in a special magical sarcophagus, where he remains for years, which leads to the opening scene of Doom 2016.

Doom 2016

Well, now we’re down to just two games left! In Doom 2016, we find the United Aerospace Corporation of Earth, led by its founder, Dr. Samuel Hayden, a way to open a portal to Hell. They discover all sorts of cool stuff, including a sarcophagus, lots of information on the Sentinels, and Argent energy. Hayden wants to use the Argents to solve Earth’s energy crisis, and is willing to put aside his devil worship if it helps. But some UAC employees are taking this whole thing a little too seriously, especially Olivia Pierce, one of the company’s researchers.

At some point, Pierce makes a deal with the demons, a deal that gives him a lot of power if they help him conquer the UAC facility on Mars where the portal was found. As Pierce probably guessed, everything goes wrong. The invasion kills almost everyone in the UAC facility, but Hayden manages to awaken the Doom Slayer, who goes back to work.

Now, you might think it’s odd that Doom Guy would fight a demon invasion on Earth, then return to Earth to fight another demon. This seems to be a function of the different dimensions in the Doom universe. Basically, Doom appears to be a multiverse, with Hell being one particular dimension and Urdak being another, and it is possible to cross over to other universes. Doom Guy started out in a universe where Mars was being invaded by demons, but by traveling in and out of Hell, he ended up in a new universe where the Mars invasion by demons had not yet happened.

Anyway, the Doom Slayer teams up with Hayden to stop Demon and Pierce, but along the way he also destroys the UAC’s ability to collect Argent energy, much to Hayden’s dismay. The Doom Slayer also tears apart Hayden’s powerful AI, Vega, and finds a powerful object called the Crucible, which he uses to ultimately stop Hell’s invasion of Mars. At the end of the game, Hayden manages to take the Crucible from the Doom Slayer, and it turns out that it is actually both an incredibly powerful Sentinel Sword and an energy source. He then uses the portal to send the Doom Slayer to an unknown location.

Doom Eternal

We don’t know what happens to the Doom Slayer between Doom 2016 and Doom Eternal, but some time will certainly pass. Hayden returns to Earth and makes a plan to save the planet using the Crucible and Argent energies. However, the demonic followers remaining in the UAC have a different plan, and soon the demons begin to conquer the Earth with the help of the UAC. Hayden and the world’s governments form an armed demonic combat force called the ARC (Armed Response Coalition) to try to repel the demons and save the Earth. However, they lose almost the entire war, and with the help of the priests of Hell, the demons begin to conquer and corrupt the Earth.

The war raged for some time until the Doom Slayer finally arrived. Somehow he came into the possession of a Sentinel spaceship called the Fortress of Doom, which he used to return to his homeworld. The Doom Slayer spends the remainder of Doom Eternal preventing an invasion of Earth by killing the Infernal Priests who are barricaded on the planet. The Hell Priests are supported by UAC operatives who have transformed into Hell Cultists to aid in the invasion.

Over the course of Eternal, the Doom Slayer kills all three priests of the Deeg Cult who betrayed the Sentinels, reunites with Samuel Hayden, recovers the Crucible and the original Sentinel Sword, and finally leaves in pursuit of Urdak to battle Kahn Maquia.

That’s it. Every Doom game is part of a longer story, except for Doom 3, which Doom 3 has nothing to do with. There are still a lot of loose ends – was Urdak destroyed? What happened to those Samurians? Was giving Hayden control of Doom Fortress a good idea? What was that other big monster hidden in the giant pond that Kahn Maykr kept in Urdak? id Software has more stories to tell in upcoming Doom titles, and when the time comes, we’ll be ready to read and explain all the collectibles.